As Krugman notes, it already happened, and workers lost in a rout:
Consider, in particular, the much-hyped “war on coal.” It’s true that getting serious about global warming means, above all, cutting back on (and eventually eliminating) coal-fired power, which would hurt regions of the country that depend on coal-mining jobs. What’s rarely pointed out is how few such jobs still exist.
Once upon a time King Coal was indeed a major employer: At the end of the 1970s there were more than 250,000 coal miners in America. Since then, however, coal employment has fallen by two-thirds, not because output is down — it’s up, substantially — but because most coal now comes from strip mines that require very few workers. At this point, coal mining accounts for only one-sixteenth of 1 percent of overall U.S. employment; shutting down the whole industry would eliminate fewer jobs than America lost in an average week during the Great Recession of 2007-9.
Or put it this way: The real war on coal, or at least on coal workers, took place a generation ago, waged not by liberal environmentalists but by the coal industry itself. And coal workers lost.
Climate change trooferism isn’t about protecting jobs.